Association of Term Labor Induction vs Expectant Management With Child Academic Outcomes

Key Points Question Does academic achievement differ in children delivered by induction at term compared with those whose mothers were managed expectantly? Findings In this cohort study, there were no differences in third-grade reading and math scores among children delivered by induction at 39 or 40 weeks compared with those whose mothers were expectantly managed past those gestational ages. Meaning These findings suggest that labor induction at term does not appear to be associated with poorer test scores when those children are in third grade.


Introduction
In August 2018, the results of the ARRIVE trial were published. 1 In this multicenter trial, low-risk, nulliparous women were randomized to either undergo labor induction or expectant management at 39 weeks of gestation. The study demonstrated a reduced risk of cesarean delivery (18.6% vs 22.2%; relative risk [RR], 0.84; 95% CI, 0.76-0.93) and hypertensive disorders of pregnancy (9.1% vs 14.1%;RR,0.64;95% CI, in the group of women assigned to induction compared with those assigned to expectant management. 1 Furthermore, induction at 39 weeks of gestation compared with expectant management past 39 weeks was not associated with an increased risk of any neonatal complication. The results of this trial have led many clinicians to begin offering elective induction to low-risk nulliparous women at 39 weeks. Prior studies [2][3][4][5][6][7][8] that examined the association between gestational age at delivery and educational outcomes usually found a benefit to delivery, in the absence of complications, no earlier than 39 weeks. Some researchers 8 have even suggested that optimal education outcomes occur when delivery occurs in the late-term period (Ն41 weeks). However, those studies used the week of delivery as the primary exposure, which is not a comparison that provides useful information in terms of prospective clinical decision-making. Specifically, because standard obstetrical care has been to await labor until at least 41 weeks, with earlier delivery initiated only if complications (eg, hypertensive disorders of pregnancy) arise, women who reach later gestational ages are systematically more likely to be without complications and, correspondingly, their children are more likely to be in better health. Thus, for example, the correct comparison in trying to understand whether it is better for children to be delivered at 39 weeks of gestation compared with a later gestation is to compare those who are delivered at 39 weeks with all those who are delivered thereafter.
Therefore, we sought to use statewide third-grade math and reading assessment scores and to compare test scores of children who were born by induction at 39 or 40 weeks with scores of those whose mothers were expectantly managed past those weeks of gestation. We hypothesized that the offspring of nulliparous women for whom labor was induced at a given term gestational age would have similar math and reading scores compared with children born to women expectantly managed past the same gestational week.

Methods
This cohort study was approved by the Rhode Island Department of Health human subjects institutional review board, which granted a consent waiver because all identified information remained at the state level. This study follows the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.
The Rhode Island Department of Education provided third-grade data obtained between 2014 and 2017 from the Partnership for Assessment of Readiness for College and Careers statewide test of mathematics and English language arts and literacy. Beginning in third grade, the examination is administered near the end of the academic year, and all students enrolled in public schools are expected to participate unless they qualify for an alternative assessment or receive an exemption.
Rhode Island's integrated child health information system, were matched using characteristics of both the child (date of birth, sex, first name, and last name) and the mother (date of birth, medical record number, and town of residence). These matched records were then directly merged with education records. Children with both birth certificate and education data comprise the study population.
For this study, we further limited the population to nulliparous women with a singleton pregnancy who were still pregnant at 39 weeks of gestation because we were most interested in the school-aged outcomes of children in the ARRIVE trial 1 (Figure). The ARRIVE trial was limited to nulliparous women, and so we did the same in this study. Children for whom a major congenital anomaly (eg, chromosomal anomalies, microcephalus, spina bifida, or gastroschisis) was listed on the birth certificate were excluded. For children who repeated third grade, data for their first test attempt was retained and later test scores were excluded.
Within this study population, we compared children who were born after induction at 39 or 40 weeks of gestation with children whose mothers were expectantly managed past that week of gestation. The gestational age of delivery was based on the best clinical estimate as entered on the birth certificate by the delivering practitioner. The birth certificate only provides week of delivery, not day of delivery (eg, 39 weeks, not 39 weeks and 3 days). Induction was determined by the intervention category on the 1989 US Standard Certificate of Live Birth (which was in use in Rhode Island during 2005Island during -2008, for which the delivering clinician could select none, stimulation (augmentation), or induction. If induction was selected on the birth certificate, the delivery was assumed to result from labor induction.
The primary outcome was third-grade math and reading scores on the Partnership for Assessment of Readiness for College and Careers examination from 2014 to 2017. Math and reading were evaluated by separate tests, and each score was evaluated both continuously as a scale score (range, 650-850) and as a binary variable using performance levels to assess competency.

Performance levels are calculated by the Partnership for Assessment of Readiness for College and
Careers administrators on the basis of a range of overall scale scores for the assessment and are used to report student proficiency. There are 5 performance levels with higher levels indicating better performance. Children at levels 4 (score, 750-784) and 5 (score, 785-850) have demonstrated readiness for the next grade level and are classified as proficient in the subject area. Children at levels Figure 1 (score, 650-699), 2 (score, 700-724), and 3 (score, 725-749) have not met expectations and are classified as nonproficient.
Maternal, pregnancy, and child characteristics that, according to prior literature, were considered to be potential confounders between the exposure and outcomes of interest in this study were evaluated as covariates. Maternal information derived from birth certificates included age, education level, smoking status, and medical comorbidities, such as diabetes and hypertension. Data on mode of delivery and birth weight were also available from the birth certificate. With regard to the child, data on race/ethnicity, city of residence in third grade (core city vs noncore area), and participation in the National School Lunch Program were provided by the Rhode Island Department of Education. Core cities were defined as cities with 25% or more children living in poverty.

Statistical Analysis
We estimated bivariable associations between math and reading test scores and induction compared with expectant management at a given gestation week.  (6)  Induction at both 39 and 40 weeks was not associated with any difference in third-grade math or reading scores compared with expectant management ( were proficient in reading. Of the children born by induction at 40 weeks, 275 (45.1%) were proficient in math and 269 (44.1%) were proficient in reading; of the children whose mothers were expectantly managed past the 40th week, 532 (46.3%) were proficient in math and 512 (44.6%) were proficient in reading.
When potential covariates were examined, there was no difference in terms of maternal age, mode of delivery, or maternal smoking status among women whose labor was induced compared with those expectantly managed ( , differed between those born by induction compared with those expectantly managed in the 40th week but not in the 39th week (Table 2).
After adjusting for confounders, induction was not associated with differences in math or reading proficiency compared with expectant management during either period. For children born by induction at 39 weeks, the adjusted RRs were 1.07 (95% CI, 0.97-1.18) for math proficiency and 0.98 (95% CI, 0.88-1.08) for reading proficiency. For children born by induction at 40 weeks, the adjusted RRs were 0.97 (95% CI, 0.88-1.08) for math proficiency and 0.98 (95% CI, 0.89-1.08) for reading proficiency ( Table 3). Core city residence at birth was not included in the multivariable model because it was associated with lunch subsidy, another measure of poverty.

Discussion
With the publication of the ARRIVE trial, there will very likely be a greater proportion of nulliparous women whose children are delivered at 39 or 40 weeks of gestation after labor induction. Although observational and trial data show that short-term outcomes of children born at these gestational ages are similar to or better than those of children born later, 1,9,10 it is also vital that the long-term outcomes of such a change are explored. To this end, we demonstrated that in a diverse population between children born at term (39 or 40 weeks) with those born late term (Ն41 weeks) and found that late-term infants scored 0.7% of an SD (95% CI, 0.1%-1.3%; P = .02) higher than did full-term infants, were 2.8% more likely to be gifted (95% CI, 0.4%-5.2%; P = .02), and were 3.1% less likely to have poor cognitive outcomes (95% CI, 0.0%-6.1%; P = .05) compared with full-term infants. 8  whether to deliver at a given time or wait beyond that time). That insight is provided by comparing women for whom labor was induced at a given gestational age with those who continued past that gestational age as we did.

Limitations
Although our study question is very relevant to potential changes in obstetric patterns over the next decade, the study does have limitations. Most importantly, although our study focused on inductions, we did not have the ability to differentiate elective low-risk inductions from medically indicated inductions. Nevertheless, it should be noted that medically indicated inductions are likely associated with worse perinatal and childhood outcomes, and this potential bias drives the comparison away from the null and favors expectant management. Yet, even with this bias, we saw no differences between the groups. Also, the data included are from a single state. Although this state's population is ethnically, racially, and socioeconomically diverse, differences between state education policies may still limit the generalizability of our findings. Our study results are further limited by the retrospective nature of the data, especially because much of the data are derived from birth certificates, leading to potential misclassification bias. Furthermore, the education outcomes are limited to third-grade scores because that is when all students in Rhode Island are tested. Ideally, we would have annual math and reading assessments for this population. In addition, the study required linking educational data to birth certificate data. Therefore, any child born outside the state, or who was born in the state but then moved out of the state, was excluded, allowing for overrepresentation of less-mobile families.

Conclusions
This a large study that addresses a clinically relevant question by comparing school-age outcomes associated with induction at full term compared with expectant management. Our results, which showed no difference in school-age outcomes with induction compared with expectant management at 39 or 40 weeks, should reassure women and health care practitioners as they consider the options for timing of full-term delivery.